<template>
    <div class="drawer">
        <div :class="maskClass" @click="closeByMask"></div>
        <div :class="mainClass" :style="mainStyle" class="main">
            <div class="drawer-head">
                <span>{{ title }}</span>
                <span class="close-btn" v-show="closable" @click="closeByButton">
                    <i class="el-icon-close"></i>
                </span>
            </div>
            <div class="drawer-body">
                <slot />
            </div>
        </div>
    </div>
</template>

<script>
export default {
    name: 'drawer',
    props: {
        // 是否打开
        display: {
            type: Boolean
        },
        // 标题
        title: {
            type: String,
            default: '标题'
        },
        // 是否显示关闭按钮
        closable: {
            type: Boolean,
            default: true
        },
        // 是否显示遮罩
        mask: {
            type: Boolean,
            default: true
        },
        // 是否点击遮罩关闭
        maskClosable: {
            type: Boolean,
            default: false
        },
        // 宽度(支持百分比)
        width: {
            type: String,
            default: '400px'
        },
        // 是否在父级元素中打开
        inner: {
            type: Boolean,
            default: false
        }
    },
    computed: {
        maskClass: function () {
            return {
                'mask-show': this.mask && this.display,
                'mask-hide': !(this.mask && this.display),
                inner: this.inner
            };
        },
        mainClass: function () {
            return {
                'main-show': this.display,
                'main-hide': !this.display,
                inner: this.inner
            };
        },
        mainStyle: function () {
            return {
                width: this.width,
                right: this.display ? '0' : `-${this.width}`,
                borderLeft: this.mask ? 'none' : '1px solid #eee'
            };
        }
    },
    mounted() {
        if (this.inner) {
            let box = this.$el.parentNode;
            box.style.position = 'relative';
        }
    },
    methods: {
        closeByMask() {
            this.maskClosable && this.$emit('update:display', false);
        },
        closeByButton() {
            this.$emit('update:display', false);
        }
    }
};
</script>

<style lang="scss" scoped>
.drawer {
    /* 遮罩 */
    .mask-show {
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        z-index: 1001;
        background-color: rgba(0, 0, 0, 0.5);
        opacity: 1;
        transition: opacity 0.5s;
    }
    .mask-hide {
        opacity: 0;
        transition: opacity 0.5s;
    }
    /* 滑块 */
    .main {
        position: fixed;
        z-index: 1001;
        top: 0;
        height: 100%;
        background: #fff;
        transition: all 0.5s;
        overflow-y: scroll;
    }
    .main-show {
        opacity: 1;
    }
    .main-hide {
        opacity: 0;
    }
    /* 某个元素内部显示 */
    .inner {
        position: absolute;
    }
    /* 其他样式 */
    .drawer-head {
        display: flex;
        justify-content: space-between;
        height: 45px;
        line-height: 45px;
        padding: 0 15px;
        font-size: 14px;
        // font-weight: bold;
        border-bottom: 1px solid #eee;
        .close-btn {
            display: inline-block;
            cursor: pointer;
            height: 100%;
            padding-left: 20px;
        }
    }
    .drawer-body {
        font-size: 12px;
        padding: 15px;
    }
}
</style>